Stock clutch specs - clamping force

[bhoulis]

Have spent some time searching the web and can't seem to find any info on factory small block clutch specs. I'm specifically interested in the static clamping force, both base 289 and hipo. It's time to pick a clutch kit for my 67 GT350 and want to stay with a Long style, non-counterweighted pressure plate. Will be street driven and looking for an original "feel" on the pedal. Going with all stock clutch linkage and don't want something so heavy that things start bending. I have a previous post up looking for the specs on an old Hays 10CF plate, circa 1981, which I have and is in almost new condition, but don't know the spec on it. Shelby Parts recommends the McLeod with an advertised static force, of 1800 lbs. Hays has their Street 450 kit, 91-2001 with 2800 lbs, according to their tech guys. Quite a difference for 2 "street" clutches. Would like to have numbers on the factory pieces to compare these to. To be honest, I haven't found any other manufacturers offering the Long style set-up. NAPA, chain store?? Any thoughts, opinions or suggestions are much appreciated. Thanks. Brian

[gjz30075]

I, too, went looking recently and found these threads helpful.   They're not talking about Hipo clutches but I've felt stock B2 clutches
and it's want I'm looking for in feel.   Nice and light.
http://www.boss302.com/smf/index.php?topic=71855.msg475331#msg475331

http://www.boss302.com/smf/index.php?topic=67292.msg445279#msg445279

I know others will chime in with good experiences.

[shelbydoug]

A stock clutch was rated at 2600 pounds. What Ford called a heavy duty clutch was 2800 pounds.

Street clutches from people like Hays were 3200.

The HD at 2800 pounds will slowly bend the stock z bar and it needs to be reinforced to avoid that. The Hays will just turn it into silly putty and you likely won't even be able to get out of the garage without the reinforcement.

I double the top curved part. When you do that, use a bucket of water to suddenly quench it when red hot. That will hardened it.

Some have been successful with not reinforcing it and just heating it continuously (three or four times) to glowing red hot, then dumping it into ice water.

Depending on the steel, you can over harden it that way and it could become brittle. I like just doubling the hook.

[bhoulis]

Thanks for the responses guys. Hopefully more will respond and we can form a consensus. Quite a range of numbers, 2800, 2600, 1575 and 1162 pounds. Modifying my z-bar is not really an option for me. 67 hipo pieces are a little too scarce. Brian

[shelbydoug]

I just supply facts that I know, experiences I've had and solutions that I've used.

The original clutch, 2,600#, was never serviced. It was production line only. If you purchased a clutch through Ford Service Parts it was the 2,800# and in my experience came from a local Ford licensed rebuilder. It was not new.

How you choose to solve the issue is your part.

For me it's "just the facts Mam".